A collaborative virtual environment (CVEs) is a 3D shared environment that supports geographically dispersed users to interact with each other. Distributed Synchronization is a mechanism to ensure the consistency of the dataset among all the remote users which are involved in the shared environment. Due to the existence of network latency among remote users in such an environment, it is difficult to guarantee that any change in the dataset will be reported timely to all remote users. As this type of dataset changes is continuously over time in nature, the inconsistency problem exists all the time. This means that remote users may perceive different views of the same virtual environment, which will substantially affect the interactivity of the collaboration.
To address the synchronization problem, we have developed a new synchronization algorithm for collaborative virtual environments. It considers how interactions with dynamic objects are perceived by the users and attempts to remedy object motion trajectories to reduce the discrepancy of shared objects. The new method can handle unpredictable user interventions and false positive and false negative collision detection problems.
A prototype has been implemented for demonstration. A pair of CyberGlovesTM with 3D trackers are used as input devices to manipulate the dynamic objects. As flow visualization and dynamic user interaction are supported in this prototype, users can navigate in the shared environment and apply force to objects to intervene a flow simulation and collision simulation.